It has long been known to use flexible blade seals of various designs, such as that shown in FIG. 1 of the appended drawings, to provide a seal between a fixed or sliding pane of a window assembly and a frame member or other adjacent surface of the assembly. Such blade seals typically have a simple cross-sectional configuration, since they are produced preferably by extrusion or other molding technique adapted to mass production of extended lengths of the blade seal. As can be seen in FIG. 1 of the appended drawings, such known blade seals typically have a sealing surface 5 provided by a sealing segment 6, which extends at an angle to the top wall 7 of a base segment 8. The base segment 8 is adapted to be attachable to a window frame or the like.
The blade seal in a window assembly must perform several critical functions. Not only must it seal out weather, that is, precipitation and wind; it must also provide an effective reduction in wind noise. Further, the blade seal must perform these functions typically over an extended time period and often under harsh environmental conditions. In window assemblies intended for automotive vehicle body applications, for example, as the rear window assembly in a pickup truck or the like, the blade seal will be exposed to both hot and cold temperature extremes, often cycling quickly from one to the other.
Difficulty in providing an effective and enduring weather and noise seal is experienced not only along the main length of a blade seal. Particular sealing problems have been experienced at the extreme ends of a blade seal, where, typically, it interfaces with other sealing members. Thus, in a typical automotive window assembly application, a first blade seal may be used along a vertical edge of the window opening fitted with a sliding pane, and additional blade seals may be used along the upper and lower horizontal edges of the window opening. Yet another blade seal may be used at the opposite vertical edge. At the four corners of the window opening, the individual blade seals must cooperate to form an effective weather and noise seal.
There is a need for more effective blade seals, providing better and more durable performance, especially in window assemblies equipped with sliding panes. There is also a need for more effective noise and weather sealing at the corners of a window opening, where one blade seal cooperates with another blade seal or other sealing member to form a continuous seal about the periphery of the window opening. It is an object of the present invention to provide improved blade seal performance to meet some or all of these existing needs. These and other objectives of the invention will become apparent from the following disclosure and description of various embodiments of the invention.